Table 3. Percentage of computed tomography use at emergency department visits with a diagnosis of upper tract urolithiasis, by selected characteristics: 1998–2009.

	1998–2000		2001–2003		2004–2006		2007–2009
	%	95% CI	%	95% CI	%	95% CI	%	95% CI	Ptrenda
Total	21	15, 26	44	38, 49	65	60, 70	71	65, 77	0.029
Age
<25	—	—	42	28, 56	53	41, 65	64	51, 77	<0.001
25–44	19	11, 27	39	32, 47	64	57, 72	73	65, 80	0.018
45–64	—	—	47	39, 55	71	62, 79	74	68, 80	0.24
>64	—	—	—	—	72	57, 86	60	45, 74	NA
P valueb	NA		0.23		0.11		0.21
Sex
Female	—	—	44	37, 51	61	55, 68	68	60, 76	0.20
Male	24	16, 31	44	36, 51	68	62, 75	74	68, 79	0.028
P valueb	NA		0.99		0.15		0.14
Race
White	21	15, 27	44	38, 50	65	60, 70	70	74, 76	0.036
Non-white	—	—	42	28, 57	66	52, 80	80	68, 92	0.10
P valueb	NA		0.88		0.88		0.11

Abbreviations: CI, confidence interval; NA, not available.

—: Data not shown have fewer than 30 records or have a relative s.e. >30% in the corresponding category.

Estimates are considered unreliable.

^aBased on weighted least squares regression analysis.

^bBased on Wald χ²-tests.